A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its power output. The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet’s resources alone. Because only a tiny fraction of a star’s energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy.

      • dependencyinjection@discuss.tchncs.de
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        3 months ago

        I believe they were making a joke because if you wrap this thing around a star there really is no day night cycle because it’s all star. Our day night cycle comes because we are spinning.

  • Spacehooks@reddthat.com
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    3 months ago

    Be carful with those. You may block the light of constellation aliens use and really piss then off.

  • Einar@lemm.ee
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    3 months ago

    You need to watch more Star Trek, friend.

    Specifically “The Next Generation”, Season 6, Episode 4, " Relics".

    Thank me later. 😁

  • M137@lemmy.world
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    3 months ago

    Some TIL posts really surprise you, it’s crazy to me that you have never heard about this. Not being degrading or anything like that, it’s just surprising.

  • batcheck@lemmy.world
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    3 months ago

    Came here to say that if you like this concept, Peter Hamilton has a book series called Commonwealth Saga in the science fiction category that is excellent. Lots of pseudoscience from early 2000s in that series.

      • rumba@lemmy.zip
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        3 months ago

        I think freeman Dyson beat em to the punch by several decades :)

        The game is truly great though.

  • Tuxman@sh.itjust.works
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    3 months ago

    I don’t remember the math, but you lose return on investment after a certain percentage of coverage.

    Dyson Grids are the future!!! 😜

    • I Cast Fist@programming.dev
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      3 months ago

      Or DYson Bubbles, which would also “cover” enough “surface” to be viable without needing god knows how many planets’ worth of material

    • Fedegenerate@lemmynsfw.com
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      3 months ago

      The other “benefit” to the sphere is blacking out a star. Other life, should it exist, is less likely to find the structure. ITT people destroying my dreams of a big shelly boi

      • Bimfred@lemmy.world
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        3 months ago

        I would think it’d make it more likely that you’re discovered when you turn your star into a black ball with a gigantic IR signature where a star should be. Any civilization with a cursory understanding of gravity and stellar spectra would turn every telescope they have on you.

        • Fedegenerate@lemmynsfw.com
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          3 months ago

          What does IR red shift into over cosmic distances? But it would be just as, if not less, noticeable as a star suddenly dimming to [100%-optimal capture rate]

          • PlasticExistence@lemmy.world
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            3 months ago

            The gravity from the star will also still be there regardless of how much of its EM signature is visible outside of the sphere.

          • Bimfred@lemmy.world
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            3 months ago

            Deeper IR, microwave and radio. Within a galaxy, redshift can be ignored. In another galaxy, the issue is moot, you don’t need to worry about them and they don’t need to worry about you.

            Our current scopes can pick up brown dwarfs with a surface temperature below freezing. An object the diameter of a planetary orbit, with the gravitational effect of a main sequence star and giving off just black body radiation is gonna stick out like a neon “Interesting stuff here!” sign the moment someone does a long wavelength survey of your general region.

            Even if you build a swarm instead of a solid shell, you’re still going to shift the star’s apparent spectrum towards IR, from the swarm radiating waste heat. A star whose mass, diameter and emission spectrum don’t match up with the math is inviting investigation, regardless of how you try to mask what you’ve been doing.

    • spicehoarder@lemm.ee
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      3 months ago

      My initial reaction: “What? No.”

      After thinking a little bit: “hmm I guess you could say that…”

      • m0darn@lemmy.ca
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        3 months ago

        Like I’m sure it’s not but I don’t know if it’s a worse explanation than any of the other ideas being considered. But I don’t know enough to even know how wrong I am.

    • cewren@lemmy.world
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      3 months ago

      While the idea is charming, a Dyson sphere itself would still consist of matter and as such it would emit radiation according to its temperature (https://en.m.wikipedia.org/wiki/Thermal_radiation). And since it surrounds a star it is heated from the inside and would definitely emit radiation that can be detected. Dark Matter is missing this radiation part and is only observed by its gravitation.

      So the answer is no, unfortunately.

      • m0darn@lemmy.ca
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        3 months ago

        Edit to add disclaimer: this is shitpost level math here guys, I’m just spitballing.

        It would definitely emit thermal radiation. if it was 99% efficient and the size of pluto’s orbit, around a star like the sun, and the energy was used to create matter, I think it would radiate the remaining energy as 0.009 W/m2 with a peak emission wavelength of 150micrometers. The James Webb telescope has infrared capabilities that max out at 28.5 micrometers so def not detectable.

        But probably a dyson sphere would be smaller than pluto’s orbit, which would greatly increase the apparent power, and shorten the wavelength. idk it’s all imaginary.

        I won’t subject you to my hand writing but I did (power of sun × 0.01)/(surface area of sphere with Pluto’s orbital radius) to get radiation intensity (0.009 W/m2). Then rearranged Stefan-Boltzmann law to solve for temperature (19.8K). Then used Wien’s Displacement Law to calculate the peak wavelength (1.5×10-4 m).

        Maybe I’ll run the numbers again with a martian orbit radius, and 50% efficiency.

        • m0darn@lemmy.ca
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          3 months ago

          Okay I did the same calculation but with Martian orbit as dyson sphere size, and 50% efficiency I got a wavelength of 3.4um so nicely in the infrared range of JWST.

          I think the sphere would need to be like 99.95% efficient to be undetectable by JWST at Martian orbit radius.

  • merdaverse@lemmy.world
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    3 months ago

    It’s a pretty cool concept, and I enjoyed building one in Dyson Sphere Program, but I don’t really understand how you would transport that amount of energy to where you need it. Are they like mirrors that redirect and focus light to some point?

    • Hadriscus@lemm.ee
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      3 months ago

      Split into several laser beams targeting a bunch of big-ass converters in line around the equator. But it would have to be extremely accurate and route a fraction of total power unless you want to pulverize earth

    • Geobloke@lemm.ee
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      3 months ago

      I guess you would store it in chemicals like oil or create radioactive substances that are optimised for specific energy decay rates

    • Quadhammer@lemmy.world
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      3 months ago

      I think the main goal is to power structures around the star and stockpile energy. End end goal would be to create a stellar engine so you can move the solar system itself

    • kerrigan778@lemmy.world
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      3 months ago

      Presumably superconductors are a given at that level of technology. But also at megastructure scale, we could easily talk about very exotic energy transfer methods. Mirrors, microwave transmission antennas, kilometer wide conduits of highly conductive “ground” material, large scale production of fusion fuel, maybe usable power from heat difference is such an efficient process at any scale that the sphere just has a hot side on the inside (towards the sun) and a cold side on the outside (towards cosmic background) and anyone who needs power just patches in a heat pipe to the inside surface.

      Actually there’s a lot there on that last one. Large efficient power plants could be built anywhere where people needed them hooked with big heat pumps into the inner surface and outer radiator surface, smaller applications could just hook into the inner surface and radiate heat passively and let the climate control deal with it. Rogue energy thieves could be tracked down by scanning for unregistered cold spots on the inner surface.

      • RizzRustbolt@lemmy.world
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        3 months ago

        Most of them use Gap Transmission to get the power from the plants to the users. That’s when they use microfolds in space to transmit power across large distances.

        Some of them more exotic methods than that though. One of them uses neurotissue harvested from Chuck as a transmission medium.